Welding is a process in which two pieces of metal are joined together using heat and electricity. A filler material is used to form a pool of molten metal that cools to become a strong joint between the pieces. Welding is used in many different industries, including construction, shipbuilding, aeronautics and electronics. There are many different welding processes, but the most common are stick welding, metal inert gas (MIG) welding and tungsten inert gas (TIG) welding.

Stick Welding

Stick welding, also known as Shielded Metal Arc Welding (SMAW) is one of the easiest and most common types of welding. The electrode, or "stick" that gives this type of welding its name, is covered with a metal coating that melts and forms a gas shield as the heat is applied, adding slag, deoxidizers and alloy to the welded metal. Slag is created when globules of molten metal solidify on the surface of the weld--these must be chipped off. Stick welding equipment is simple to use and inexpensive. The electrode provides its own flux, eliminating the need for additional supplies. Stick welding can be used in all positions (welding done flat, horizontal, vertical and overhead) and has a lower sensitivity to drafts than gas-shielded welding. However, these welds have a very rough appearance.

MIG (Metal Inert Gas) Welding

Metal inert gas, or MIG, welding uses a spool of solid-steel wire that is fed to the work area from a machine through a contact tip in the MIG “gun.” The contact tip is electrically charged when the trigger of the gun is pulled, which melts the wire for the weld puddle. MIG is usually used in indoor welding where drafts will not displace the gas shielding. However, it can be used in the field with wind blocks, such as plastic sheets. MIG welding can be used on stainless steel, mild steel and aluminum. It can be used to weld in all positions. You do not have to chip off slag build-up, and it is relatively easy to learn, according to TheFabricator. Disadvantages include having to use a cumbersome tank of shielding gas and the cost of consumables like tips and nozzles.

TIG (Tungsten Inert Gas) Welding

Tungsten inert gas, or TIG, welding can be used on a wider variety of materials, provides very high quality welds and does not produce toxic smoke or fumes. The argon gas used in this process protects the weld from contamination, so no slag is produced. Welds can be done in all positions. All of these benefits make TIG welding an ideal choice for confined spaces, according to MillerWelds.com. TIG welding requires more skill and experience to produce a good weld, however. The torch must be held at the right angle, the weld-pool must be kept uniform and the right filler must be used.